Valve for pneumatic tires



July 8, 1941. R. F. MATTHEWS VALVE FOR PNEUMATIC TIRES Filed Aug. 1Q,1938 gmc/YM 245. l/l/l//l/A Patented July 8, 'ldt stares PATENT VALVEFOR APNllUllIATICl TIRES Richard F. Matthews, Norvell, Mich.

Application August 10, 1938, Serial No. 224,009

I Claim.

The present invention relates to an inating valve for pneumatic innertubes for pneumatic tires, being particularly concerned with a cellularor multi-compartment type of inner tube,

Heretofore cellular and multi-compartment inner tubes have been proposedto facilitate repair or replacement, as well as to eliminate to somedegree the hazards connected with a blow- According to the presentstructure a multi-4 compartment inner tube is provided having radial ortransversely disposed extensible partitions or bulkheads which aredisplaced circumferentially of the tube upon diierential reduction ofpressure in adjacent compartments so as to effect displacement of theadjacent compartments into the space Vformerly occupied by an iniatedcompartment in which the pres-r sure has 'been reduced. In the preferredform, each ,compartment of the tube is capable of being individuallyinated or jdeliated through a common air distributor.

Thus, one of the objects of the invention re-v sides in an improvediniiating valve for an inner tube for pneumatic tires having a pluralityof of pneumatic tires.

circumferentially spaced partitions or bulkheads V dividing the tube upinto separate compartments 1 and capable of expanding into one anotherupon relative reductions in pressure in adjacent compartments as mightresult from a puncture or blow-out, and whereby theination of the tire Yis equal.

Other advantages and objects of the invention residing in the specificarrangement, construction and combination of parts will be hereinafterset forth in connection with the detailed description and embodied inthe annexed claim,

In 4the drawing- Fig. l is a side elevational view of the preferred formof an inner tube partly shown in broken section,

2 is a cross-.sectional view taken on line II-II of Fig. 1,

Fig. 3 is a partial cross-sectional view taken on line III-411 of Fig.4, of the distributing valve,

Fig. 4 is a plan view of theair v distributor -asis substantiallymaintained notwithstanding the sembly vulcanized in the preferred formof the tube,

Fig. 5 shows my vmethod of vulcanizing the.

partition or bulkhead Within the tube, and

Fig. 6 is a cross-sectional view of a modified v form of a bulkhead witha port.

Referring to the drawing, in Fig. 1 is shown a pneumatic rubber tubegenerally designated .by the reference character I0, the tube being'ofthat type conventionally used for the inflation Circumferentially spacedwithin the outer wall I2 of the tube I0 are partitions of bulkheads Itsuitably vulcanized or molded in situ. Preferably, the partitions It arefabricated from readily stretchable sheet rubber so as to haveconsiderable stretch or ex pansion when one side only is subjected tothe normal pressures of inflation for pneumatic tires.

In the illustrated form, the partitions It are im-v pervious, althoughit is anticipated that very minute ports may be provided in thepartitions I4 to assure equalization of the air pressure in eachcompartment I6 during operation. It is to be understood, however, thatthese minute ports would not interfere with the characteristic op-veration of the partitions I4 which takes place upon sudden relativereduction .in pressure in adjacent compartments, but would merely permitla very slight amount of air to pass from one and 28, as shown in Fig.4, which communicate with ports 3l of the valve stem 20. To balance theassembly as much as possible,v the strip I8 may be extended aroundthe.'ent'ire inner circumference of the tube I0, as shown, with theopposite ends thereof meeting at 33. passages 22, 24, 26 and 28 are-sealed in a suitable manner, not shown, at the opposite ends of thestrip I8. Suitable punched or molded holes 32 inthe Wall I2 .o'f thetube I0 register with the ports 34, 36, 38 and 40, which open into thepassageways 22, 24, 26 and 28, respectively. It will be noted that thereis no direct intercommunication betweentthe ycompartments I6 through thepassageways 22,126, 26 land 28 other than through the valve mechanism.

'I'he valve stem 20 comprises a metal insert t2 separately molded andthen vulcanized together. In this connection, it is also feasible tofabricate the tube wall I2 with an integral thickened The strip portioncarrying the passageways shown in the strip I8. A valve core 46 isthreaded into the insert 42 at 48, with the lower end 5|! of the pin 52of the core 46 directly adjacent a semispherical seat 53 into which theports 3l open. A rubber valve 54 'fitting seat 53 is continuously urgedagainst the said seat 53 by a spring 56 to close the ports 3l. A plug 58functions as a seat for the spring 56 and is provided with a port 60through which air passes in connection with the inflation and deflationof the compartment directly behind the stem 20 and in directcornmunication therewith. When the pin 52 is depressed` by an air chuckfor inating the tube or by the special cap 62, as illustrated in Fig. 3,or is depressed in some suitable manner to exhaust air from the tube I0,the lower end 5U will unseat the valve 54 and open the ports 3|. As theport 60 opens into the chamber defining the seat 53 with the valve 54removed from its seat, the port 60 will be in communication with thesame conduits as the ports 3| with the result that air will be admittedand exhausted from the tube compartments into which the port 60 opens ina manner similar to the tube compartments with which ports 3|communicate. Thus it will be seen.- that by supplying air to the innertube I0 by means of an air chuck connected to valve 20, air may beequally directed into each compartment I6. The cap 62 may be used toequalize the pressure between compartments, and various means may beused to depress valve pin 52 to exhaust air from all of the compartmentsI6.

I2 of the tube. With the tube turned wrong side out. it is threaded overand then down through a ring II),'backing up the vulcanizing operationof the partition I4 in its proper place within the tube. A heated platen12 is used for applying the required heat and pressure for thevulcanizing operation.

In Fig. 3 is shown a special cap 62 which when screwed entirely downupon the threaded valve stem 20 will seal the air pressure in the tubeI0, while at the same time the projection 64 depresses the pin 52, whichin turn forces the valve 54 from its seat, permitting equalization ofthe pressures in the several compartments I6 for the reason that ltheports 3| and 60 are then in communication with one another for the freeflow of air to areas of lower pressure. In practice, the cap 62 wouldonly be used to depress the pin 52 following inflation of the tube I0.At al1 other times the cap 62 would be merely backed offv upon thethreads of the stem 20 sufficiently to have the projection 64 clear theend of pin 52.

In dotted outline in Fig. 1 in the uppermost compartment I6 the definingpartitions or bulkheads I4 are shown expanded into the formercompartment space following a reduction of pressure therein as mightresult from a puncture or blow-out. Obviously, lling in the formercompartment will result in the pressure in all remaining compartmentsbeing somewhat lowered, yet well within an operating range. No attempthas been made to indicate by dotted line representation the extension ofthe remaining partitions I4 that will necessarily take place. A blowoutor puncture in any one compartment I6 will in no way interfere with theoperation of the running wheel equipped with my improved tube, the onlyeffect being a slight but relatively uniform reduction in pressurethroughout the entire tube. While prolonged operation of 3. tire havinga tube with a collapsed compartment is not intended, several hundredmiles travel following a blow-out in one compartment is found to have noappreciable detrimental effect upon the partitions I4, which expand tofill in the col- The representation in the drawings of five compartmentsI6 is merely for purposes of illustration, and-it is not my intention tolimit the tube to any particular number of compartments. Experimentshave indicated that as few as three compartments in a standard sizeinner tube will give satisfactory results, particularly if thepartitions I4 are fabricated from rubber sheeting capable ofconsiderable extension without rupture under normal tire pressures. Byincreasing the number of compartments IB, the amount of extension of thepartitions I4, in order to fill a collapsed compartment, is obviouslyreduced and less attention need be given to the physical construction ofthe rubber sheeting from which the compartments are fabricated. Themethod disclosed in Fig. 5 is only one of several ways to manufacturethe tube.

In Fig. 6 is shown the partition I4 with a very minute equalizing port'I4 which has been very materially exaggerated in size in the drawingsfor the purpose of illustration. The function of the port 14 is toinsure equalized pressure in all of the compartments of the tube. Inpractice the port 'I4 will be reinforced in any well known manner so asto prevent enlargement upon expansion or extension of the partition I4such as would take place upon a puncture or blow-out resulting in acollapse of one of the compartments. It is to be understood that theamount of air that escapes through the port 'I4 is exceedingly small andshould the wall I2 of the tube be blown out or punctured it would take aconsiderable period of time for the tube to be deflated and that thepartition I4 would function in the same manner as the partition I4 asdescribed and illustrated in Fig. 1 upon collapse of one of thecompartments.

Having described my invention, what I desire to protect by LettersPatent and claim is:

A valve for pneumatic tubes having a plurality of separately inflatedand deiiated compartments comprising a valve stem, a valve core having apin and located in said valve stem, an air passage through said valvestem and controlled by said valve core. a plurality of portscommunicating with said air passage and adapted to communicatewith thetube compartments, said ports being defined in a common wall structureand opening into a common chamber, a cap received upon the outer end ofsaid valve stem and having a seat portion adapted to seat against theouter end of said valve stem to seal said air passage above said 'valvecore, said cap having a portion engageable with said valve core pin todepress the same with said cap seating upon the outer end of said valvestem, valve means for said ports located in said common chamber andoperatively connected with said valve core pin for placing said portsinto communication with one another when said valve core pin isdepressed by said cap, said valve means in one position closing saidports and in another position opening said ports for communicationthrough said common chamber when said valve core pin is depressed toopen said valve means.

RICHARD F. MATTHEWS.

